1. Field of Invention
The present disclosure relates to a power driving circuit of an LED (light emitting diode) load. More particularly, the present disclosure relates to an LED driving circuit with overvoltage protection and overcurrent protection.
2. Description of Related Art
Currently, in order to keep consistent lamp brightness of the LED (light emitting diode) load, most of LED lamp manufacturers select a control manner in which a current passing through the LED is constant. When a power conversion module is not connected to the LED load, no current is generated since no loop is formed at an output end of the power conversion module. At the moment, for example, under the action of a negative feedback circuit, an output voltage of the power conversion module is boosted, and is likely to exceed the maximum load voltage that the LED load can bear. If the LED load is introduced into the power conversion module in a hot swapping manner, the introduced LED load causes damage to an LED lamp due to an overcurrent.
In order to solve risks of damage to the LED load above, the manufacturers often mark or note at an eye-catching position that electrical detachment between the interface of the LED load and the interface of the power conversion module is not allowed under normal operation state of the power driving circuit. However, in the conventional techniques, a user often privately separates the power conversion module under the operation state from the LED load and then reconnects the same. According to the circuit analysis process above, such violation operation behavior doubtlessly causes overcurrent damage to the LED load, and this is because that the output voltage of the power conversion module is very likely to be boosted far beyond the maximum load voltage that the LED load can bear, so that a high current peak value is formed in a short time after a circuit loop is formed.
In view of the above, many in the industry are endeavoring to find ways in which to design an LED driving circuit, in which under a no-load normal operation state of the power conversion module, even if a user plugs in or removes the LED load to the output end of the power conversion module on line, no overcurrent damage is caused to the LED load, thereby realizing dual protection of the power conversion module and the LED load.